简单输出

#include <stdio.h>

int main()
{
prontf("Please enter your name \n");
return 0;
}

计算圆的面积

#include <stdio.h>
#define PI 3.14
double calculateVolume(int radius);
int main()
{
    int cRadius = 0; 
    double volume = 0.0; 
    printf("请输入圆的半径: \n");
    scanf("%d", &cRadius);
    volume = calculateVolume(cRadius);
    printf("圆的面积是：%f \n", volume);
    return 0;
}
 double calculateVolume(int radius)
 {
    double result = PI*radius*radius;
    return result;
 }